The 'Irish cop with an exaggerated brogue' joke, as seen with Chief O'Hara on Batman, and just about every movie or TV show made before about 1960.
There was a Beverly Hillbillies episode, where the Clampetts are visiting New York City, and decide to stay in Central Park. Granny is befriended by an Irish cop, who believes the Clampetts are also from 'the old sod', and the policeman promises to bring his sergeant to meet them. They leave shortly before he gets there, and the sergeant..played by Sammy Davis Jr., doing his best Pat O'Brien impression...says he's sorry he missed them...and breaks into 'Toora Loora Loora'. ;D